Project Summary This request is in response to NOT-AI-20-031 for supplement funding in response to the CoVID- 19 emergency. COVID-19, the infectious disease caused by SARS-CoV-2, is rapidly affecting humans around the globe. While initial epidemiological data have focused on cases that resulted in severe respiratory disease seen predominantly in adults, little information regarding the infection burden in children is available. This is complicated by the observation that many virologically-confirmed cases in children are asymptomatic. Undocumented, and likely infectious, cases could result in exposure to a far greater proportion of the community than would otherwise occur. Indeed, it has been proposed that undocumented (or silent) infections are the source for almost 80% of documented infections; thus, it is critical to determine the silent and symptomatic infection rate in children. To overcome challenges for clinical study implementation imposed by current healthcare access restrictions, a surveillance study under design will enroll and prospectively observe eligible children, and their family members, that are current participants in our NIH-funded, ongoing, birth cohort studies. These children and their families are known to research staff and as part of their participation in HFHS studies, they have already been exposed to the procedures involved in a surveillance study. We are requesting support for the pediatric studies aligned with our Microbiota and Allergic Asthma Precision Prevention (MAAP2) (PI: Johnson, Ownby P01AI089473) to participate in the multi-center survey entitled Human Epidemiology and Response to SARS-CoV-2 (HEROS), Protocol # DAIT-COVID-19-001. Our primary objective is to report the incidence of SARS-CoV-2 infection (detection of virus in nasal secretions) over time in cohort children (index child) and household contacts (caregivers and siblings). A secondary objective is to compare SARS-CoV-2 infection status and antibody development for index children/siblings with atopic conditions (e.g. asthma, eczema) versus children without atopic conditions. As an exploratory aim, we will investigate whether SARS-CoV-2 infection (as determined by virus detected in nasal secretions) is associated with the presence of virus in stool. Our targeted enrollment is 300 families recruited over a 2-week period and followed for a minimum of 6 months. At predetermined intervals, biological samples (nasal swabs, peripheral blood, stool) will be collected by the caregiver at home using materials provided to the family. Symptom and exposure surveys will be completed remotely via a smart phone, on-line, or telephone at the time of biological sample collection. This timely, multi-site study can be rapidly implemented and realistically conducted without necessitating any visits to a clinical research center and will provide invaluable information on the infection burden of SARS-CoV-2 in children.